Problem: William eats at a cafe and the cost of his meal is $\$42.00$. He would like to leave a $5\%$ tip. What is his total bill including tip?
Answer: The tip amount is equal to $5\% \times \$42.00$ We can find the tip by first calculating a $10\%$ tip and then dividing that number by two. To calculate a $10\%$ tip, move the decimal point in $\$42.00$ one place to the left. $10\%$ $\times \$42.00$ $\$4.20$ To calculate a $5\%$ tip, divide the $10\%$ tip amount in half. $5\%$ $\times \$42.00 = $ $\$4.20$ $ \div 2 = $ $\$2.10$ The cost of the meal plus the amount of the tip will equal the total bill amount. $\$42.00 + \$2.10 = $ $\$44.10$ The total cost of the bill is $\$44.10$.